The midfielder has recently ended a five-year period contracted to the Blues, the majority of his time spent out of favour or away from the club.
Despite being signed for a fee in the region of £35m in 2017, Drinkwater is now a free agent, a consequence of not representing the West Londoners since August 2018.
Less than a month after that 30-minute appearance in the Community Shield, the Englishman is said to have learned that he did not feature in the plans of Maurizio Sarri, who had been appointed during the previous month.
Speaking to Sky Sports News, Drinkwater has opened up on his bewilderment at the situation at a time when he was working to impress the Italian.
The 32-year-old said: "It got to the last hour of the transfer window and [I] got pulled into the office, not expected at all. 'Don't think you're going to be in our plans'. This is Sarri, being translated by Gianfranco [Zola]. And I was like 'what?'
"Sarri and I got on like a house on fire off the pitch. On the pitch, we were like chalk and cheese. I was like - 'why are you telling me now? An hour before the window closes? I need time'. He replied, 'No, no, we've got clubs abroad you can look at'
"My reaction was - 'No, I've got my young son. He is my priority'. So I decided to stay until January."
Instead of signing for a new club during the 2019 winter transfer window, Drinkwater remained in West London, failing to make another appearance that season.
A year on from his last outing for Chelsea, Drinkwater moved to Burnley on loan, but it was the first of several loan periods which did not pay off for the player.
Having featured on just two occasions for the Clarets, Drinkwater left for Aston Villa later in the season where he made just four appearances in all competitions.
Even with Sarri having left Chelsea, Drinkwater remained out of the picture, and he spent the second half of 2020-21 at Turkish side Kasimpasa, playing 11 games in the Super Lig.
In terms of regular game time, the last campaign was Drinkwater's most successful as he made 23 appearances in the Championship with Reading.